281–290 of 356 posts
If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.
Earlier quoted context omitted.
edit-too-late-to-edit: I remembered something that makes me think it's actually more complicated. If I write 0 and 1 on two different pieces of paper, then flip a coin to decide which paper to give you, we have "entangled" unknowns. When I reveal my paper, we instantly know what's on yours. The joint distribution can't be described per-particle, but we don't consider it spooky. So I think there's something more to it…
Because your example does not contain superpositions. With entanglement the pieces of paper are both 0 and 1 at the same time until they are observed - and only then is it that the superposition of both particles become resolved.
If we were in a simulation, would the speed of light be the processing speed of the universe as each area re-renders, and spooky action at a distance be two variables pointed to the same memory location, populated with a lazy-loaded value, with copy-on-write semantics? edit: seems like it is lazy loaded, so revised my summary.
That's not a bad analogy, but you have to be very careful here because no classical analogy can be a perfect fit for entanglement. The wave function is deeply and fundamentally different than our classical reality, and there is no way to reproduce its behavior classically. Among the fundamental differences is the fact that classical information can be copied but quantum states cannot be cloned. This is IMHO the singl…
Couldn't that 'hidden variable' be just another dimension? So while those particles might have been separated in space by a large distance, on that fifth dimension they haven't moved and are still sitting side by side.
Bell's theorem is strong: No local hidden variables can explain quantum entanglement. Your proposed fifth dimension is exactly such a variable – there is no set of values it can take on that explains the quantum phenomena we can easily and reliably observe. The fact that you think of it as a distance itself isn't important to Bell's theorem. Such a theory is cannot even obey relativity in our existing 3 dimensions (o…
Earlier quoted context omitted.
That's not a bad analogy, but you have to be very careful here because no classical analogy can be a perfect fit for entanglement. The wave function is deeply and fundamentally different than our classical reality, and there is no way to reproduce its behavior classically. Among the fundamental differences is the fact that classical information can be copied but quantum states cannot be cloned. This is IMHO the singl…
A classical analogy for entanglement: suppose I have two balls in a bag. They are identical in every way, except one is red and the other is blue. I randomly grab one in each hand and show my hands closed. Now the states of the ball are entangled: as soon as you see the color of one ball, that "determines" the color of the other. (Not claiming that this is a perfect analogy, but I don't see where it diverges from how…
Bell showed that the correlation is even greater than you can get using that sort of thinking. Reality is more like this:
Bob and Alice each get a pair of bags, one black and one white. They open one of the bags in which they get either a red ball or a blue ball.
If they both choose the white bags, their balls are different colors. However if either or both of them choose the black bag, the colors of the balls are the same.
If you think about it, there's no way to put the balls in the bags to satisfy these conditions in all cases. This is a simplification of what's going on with Bell's theorem.
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I've quoted it before but I will again just because I hate superdeterminism so much: First, the logical flow: Bell’s theorem proves that no local, realistic theory can reproduce the predictions of quantum mechanics. It does so by considering a very specific situation of entangled particles being measured by spin detectors set at different angles. Critically, the angles of these spin detectors are assumed to be set in…
> And that it’s possible that these things have conspired (unknowingly) to make sure that my detector settings and a particle’s spin measurement is correlated in a particular way in my lab in a law-like way. Yes exactly, which is to say that your instrument calibration dicated by that elaborate randomization process, just ensures that the particle will arrive in a specific configuration, which is a purely local, real…
Earlier quoted context omitted.
A classical analogy for entanglement: suppose I have two balls in a bag. They are identical in every way, except one is red and the other is blue. I randomly grab one in each hand and show my hands closed. Now the states of the ball are entangled: as soon as you see the color of one ball, that "determines" the color of the other. (Not claiming that this is a perfect analogy, but I don't see where it diverges from how…
Reviewing Bell's theorem - described in this article - has resulted in experimental evidence that all classic analogies in the style of "some state was embedded in each particle at the moment of entanglement and the measurement just revealed something about what was in that single particle locally at that time" can not be true. Bell's theorem describes the highest possible upper bound of correlations for spin measure…
Earlier quoted context omitted.
It's kind of interesting how people who would never consider a creationist explanation seem quite willing to embrace the idea that we're in a simulation.
One is an assertion with no logic to justify it, the other is an assertion with a somewhat persuasive argument justifying it [1]. They are simply incomparable. [1] https://www.simulation-argument.com/simulation.html
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> It's a statement of the Everett/relative state/many worlds interpretation No, it isn't. I've said nothing about many-worlds, only reversibility. And on that point everyone agrees. > Now it's dinner time, you don't believe that You really need to read the link above. It goes into all that in great detail. But the TL;DR here is that if it's dinner time, you haven't actually reversed the measurement, notwithstanding y…
> You really need to read the link above I don't like claims to authority, but maybe you should read the papers I've published about Bell inequalities too? :-p It sounds like you're saying that, in principle, physical processes are all reversible. (Although that is often thermodynamically impossible in practice.) You're also saying that it's impossible in principle for someone to learn the result of a measurement in…
How am I supposed to do that? You haven't provided and references and your profile is empty.
> in principle, physical processes are all reversible
Correct. This is a straightforward mathematical property of the Schroedinger equation.
> it's impossible in principle for someone to learn the result of a measurement in the morning, then unlearn it when the measurement is reversed during the afternoon
That's right. But that's not because it's impossible to reverse the measurement. It's because when you reverse a measurement you don't just "unlearn" the result.
You really should read the reference I gave you.
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Correlations only but no useable communication. You can both make a decision on the same random info that isn't determined until later when you are apart, but can't know anything other than that if they followed the plan they made their choice based on the same later-determined random info, correlated with your random info. If they didn't follow the plan and measured orhogonal/same (can't remember which) spins, then…
If we agree before parting that one of us is going to Alpha Centari and the other is staying on Earth and going to assassinate either the President of Russia or America depending on the observed state on an entangled pair of particles, once I reach the star system. Doesn't the traveler have more information than anyone else on ship about whether an assassination attempt was made in Russia or America? and have it fast…
You can take actions that will later turn out to be correlated with each other, but you can only find that out once you meet up again, bounded by the speed of light.